Abstract
We described liver tissues of the long-whiskered catfish Pimelodus maculatus using histological techniques through structures stained with hematoxylin and eosin. The main aim was characterize the tissues and eventual changes, since this organ has a notable sensitivity to change in altered aquatic systems. The liver has a parenchyma divided into irregular lobules containing the exocrine pancreas (hepatopancreas) that have pancreatic cells arranged around a branch of the portal vein. The hepatocytes are diffuse and arranged in cords. The organization of exocrine pancreatic tissues is similar to the acinar morphology of many teleosts. Six types of liver alterations were found: 1) cytoplasmic vacuolization; 2) congestion; 3) inflammatory infiltrated; 4) infiltration of adipocytes; 5) steatosis; 6) cytoplasmic granules. Incidence of melano-macrophage centers were observed in the liver, suggesting an immune response to contaminants. However, we cannot associate directly such changes with the eutrophic conditions of the reservoir because we have no available reference area to compare. These findings are baseline contribution that enable comparisons with similar fish species in other tropical aquatic systems in further studies
Highlights
The liver is one of the most important organs of fish, because it plays a key role in the metabolic and biochemical processes associated with feeding ingestion or dealing with pollutants in the waters (Liebel, Tomotake, & Oliveira-Ribeiro, 2013; Ostaszewska, Chojnacki, Kamaszewski, & Sawosz-Chwalibóg, 2016)
The main alterations found in the liver were cytoplasmic vacuolization (Figure 1b), congestion (Figure 1d and Figure 2b), inflammatory infiltrated (Figure 1f, g, and Figure 2b), infiltration of adipocytes in the pancreas (Figure 2d, f), steatosis (Figure 1d, g), and granuloma (Figure 1b)
The majority of the alterations found in the liver were stages I and II, i.e., the tissue varied from slightly to moderately damaged
Summary
The liver is one of the most important organs of fish, because it plays a key role in the metabolic and biochemical processes associated with feeding ingestion or dealing with pollutants in the waters (Liebel, Tomotake, & Oliveira-Ribeiro, 2013; Ostaszewska, Chojnacki, Kamaszewski, & Sawosz-Chwalibóg, 2016). The growth in anthropogenic activities associated to industry and agriculture has increased pollution of aquatic ecosystems. This issue has raised concerns worldwide over the last decades. As fish are continuously exposed to chemicals in polluted waters, they could be used as biological markers of pollutants in aquatic systems (Milošković & Simić, 2015). In this sense, eutrophication is a potential environmental stressor, which alters the fundamental ecological processes that structure freshwater communities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
